2.8/3.1 Performance chip/module

I have an 88 GP SE with a 2.8 (I'm rebuilding a 3.1 for it, I just need some pistons for it and it's done). Well on eBay for instance you can find the modules all over the place, I was wondering if they actually work at all? Has anybody actually ever tried them? I know my 2.8 isn't a power house, nor will the 3.1 be, I just love the car (grown on me after all the work I've had to do to it... Motor..Trans..Suspension..etc) and want to get as much out of that little motor as I can.

As it has been said before those so called chips are crap. Before I knew better I bought one of thos perfomance chips and promised to boost your hp by 25 all it ended up being is a resistor. So be very wery of those on ebay.